1. Field of the Invention
The invention relates to a connecting system having at least one connector for a filter cassette that can be inserted into a filter holder and that has one or more filter layers arranged between two end plates, and having seals that are arranged between the filter layers and/or between the end plates and a respectively adjacent filter layer.
The invention further relates to a method for applying a pretensioning force to a filter cassette that can be inserted into a filter holder and that has one or more filter layers arranged between two end plates, and having seals arranged between the filter layers and/or between the end plates and a respectively adjacent filter layer.
2. Related Art
Filter cassettes, such as those used for purification processes using membrane adsorbers or for filtration processes, such as deep-bed filtration, ultra-filtration and micro-filtration, consist of one or more filter layers arranged between two end plates with seals arranged between the filter layers. To perform filtration, the filter cassettes are inserted between two clamping plates into a filter holder, such as is known from DE 37 08 733 C2 or from the company brochure for the “SARTOFLOW® 10 Stainless Steel Holder,” and an adjustable contact-pressure force is applied. After the filtration process, the contact-pressure force is removed from the one or more filter cassettes by releasing the clamping plates. This can occasionally result in undesired leakage from the filter cassette, despite the seals arranged between the filter layers.
US 2013/0118971 A1 and DE 2 028 325 A disclose directly applying the contact-pressure force required for filtration, via the end plates of the filter cassette, using appropriate bolts, that are tightened.
One disadvantage of this is the relative difficulty of precisely and reliably adjusting the contact-pressure force in accordance with the requirements of the specific process. Another disadvantage is that these known filter cassettes cannot be inserted into the known filter holders due to their rigid bolt connections.
DE 1 966 108 C3, for example, discloses a latching system for cable ties in which a series of latching teeth is arranged on an elongated, flexible strap. For latching purposes, a head arranged at one end of the strap and having a latching opening and a latching tongue (toothed clamp) matched to the strap is fit latchingly onto the other end of the strap.
An object of the present invention is to improve the known filter cassettes so that, before insertion into a filter holder and after removal from the filter holder, on the one hand, slippage of the individual components is rendered impossible and on the other hand, leakage of medium from the filter cassette is reliably prevented.
A further object of the invention is to improve the known method for applying a contact-pressure force to the filter cassette to prevent the aforementioned disadvantages.